We simulated emission using both retarded-vacuum-dipole [1]}, as in [2]}, and force-free [3]} magnetic-field geometries, as in [4]}.
Then we computed light curves and Stokes parameters for magnetic inclination angles \(\alpha = 45^{\circ }- 80^{\circ }\) , with \(5^{\circ }\)  resolution for vacuum and \(15^{\circ }\)  resolution for force-free magnetospheres, and observer viewing angles \(\zeta = 55^{\circ }-80^{\circ }\)  (both with respect to the rotation axis).
These ranges of \(\alpha \)  and \(\zeta \)  bracket the viewing angle of \(60^{\circ }-65^{\circ }\)  suggested by modeling of the X-ray torus [5]}.
Following [2]}, [7]}, and [8]}, we assume that the photon electric-field vector is parallel to the electron acceleration at each point along the field line to determine the Stokes parameters.
